What constitutes breach of the implied covenant of good faith and fair dealing?

As earlier noted, the authorities hold that breach of implied covenant of good faith and fair dealing involves something beyond breach of the contractual duty itself. Again, as recited in Gruenberg v. Aetna Ins. Co., supra, 9 Cal.3d 566, 108 Cal.Rptr. 480, 510 P.2d 1032, an insurer's responsibility to act fairly and in good faith in handling an insured's claim "is not the requirement mandated by the terms of the policy itself--to defend, settle, or pay. It is the obligation ... under which the insurer must act fairly and in good faith in discharging its contractual responsibilities." (Id., at p. 573-574, 108 Cal.Rptr. 480, 510 P.2d 1032, emphasis added.)